This invention relates to a texturized coating for protecting bare or coated metal and particularly to such a coating which will prevent damage to bare or prepainted metal surfaces of coil, or sheet, especially through marring, scratching, burnishing and cutting.
Galvanized steel, aluminum, cold rolled steel, and other metal substrates for use in the automotive, industrial and residential building, appliance, and other metal products fabricating industries are frequently finished using a continuous coil painting process. In such a process, the continuous coils of metal are uncoiled, cleaned, chemically treated, and coated with one or more coats of protective and/or decorative paint, baked to cure or dry the paint, then recoiled for future handling, shipment, and fabrication into the desired end product.
The painted top and bottom surfaces of the metal coil or sheet come into contact with each other either in the painted coil before fabrication, or when roll-formed or otherwise fabricated sheets or parts are stacked for subsequent handling or shipment. During handling and shipment of both painted coils and fabricated parts, the painted surfaces often rub against each other due, for example, to vibration, slippage in the coil, shifting in a stack of sheets or similar causes. When this occurs, one or both painted surfaces may become marred or burnished, and in some cases, the surfaces are severely scratched or even cut through to bare metal. This surface damage results in an unsightly end product, frequently requires a costly touch-up painting operation, or in the worst cases, the coated metal must be rejected and scrapped.
Surface damage, such as burnishing, marring, or scratching can occur during recoiling of the painted coil, during slitting to desired width, during stacking of parts after fabrication of the painted coil, and during movement of stacked fabricated sheets or parts from one location to another. One common solution to this problem has been to interleaf the coil and/or the stacked parts with paper or plastic sheet. This, however, is costly, and results in an additional problem of disposing of the used interleafing material. In addition, the interleafing material may stick to the painted surfaces during storage, absorb water or chemical substances that may stain the painted surfaces, and in some cases the interleafing material may actually emboss the painted surfaces if there are any folds or other imperfections in the interleafing material.
The invention described herein provides a new and unobvious solution to the problem and reduces or eliminates the possibility of damage to bare or prepainted metal surfaces. Although texturized coatings, for example including "Acrawax", have previously been used to disguise or cover marrings on metal surfaces or for aesthetic purposes, they were neither intended nor designed to eliminate marring.